Apparatus and method of fastening a latch mechanism in a vehicle door

ABSTRACT

A vehicle door comprising a strengthening structure, an inner door skin and a latch mechanism to be housed within the door, said mechanism having engagement means that co-operate with the strengthening structure to allow the mechanism to be presented for rigid fixing within the door after the inner skin has been positioned relative to the strengthening structure; wherein at least one fixing means rigidly holds both the inner door skin and the latch mechanism to the strengthening structure.

[0001] This application claims priority to Great Britain patentapplication No. GB 0201215.1 filed on Jan. 21, 2002.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a vehicle door, and inparticular to an apparatus and method for locating and fastening a doorlatch within such a door.

[0003] A typical vehicle door comprises an inner skin having an apertureand an outer skin. The aperture is provided to allow a door latchmechanism to be mounted directly onto a locally reinforced fixing areaon the inner skin. A strengthening structure such as side impact bar maybe fixed to the inner skin. The outer skin has little impact strengthcompared with the inner skin. During assembly of the door, the apertureallows the latch mechanism too be appropriately positioned within thedoor by an assembly worker or machine, prior to rigid fixing of thelatch mechanism to the inner door skin, usually by three or so screws.

[0004] The impact strength of vehicle doors during both head on and sidecollisions is of paramount importance. While, traditional doors withimpact bars fixed to an inner door skin provide improved protection forvehicle passengers their performance is limited by the strength of theinner door skin. A new type of vehicle door has been proposed, such asin PCT Application WO 01/23201 A1, where the strength of the door isprincipally provided by an inner structural member typically comprisinga bar type frame with one or more cross members. Part of the frame mayhave a generally “U-shaped” cross section to provide runner means formounting a retractable glass window. Such doors preferably have a thincontinuous inner skin to provide a seal, but this is insufficientlystrong or stiff to support the loads required for a latch mounting.Hence, in such doors it is necessary to attach the door latch directlyto the structural member.

[0005] During assembly it is necessary to position the latch mechanism,albeit non rigidly, such that when the inner door skin has been fixed tothe structural member and outer door skin have been positioned ready forfixing to the structural member the latch mechanism is maintained in aposition which allows a fixing member to be inserted through holes inthe outer door skin and strengthening structure and engage a thread inthe lock mechanism, but equally allows the latch position to becontrolled by the fixing member when it is tightened. This presents aproblem as the latch mechanism cannot be held in position by an assemblyworker or machine during assembly, unless the inner skin is fitted afterthe latch mechanism. This is disadvantageous as it requires extra fixingmeans and in particular as it is often necessary to verify the fixingtorque of the latch after assembly of other components since this is asafety critical item.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide improved doorlatch mounting means for vehicle doors. Another object is to provide alatch system for a vehicle door that has improved resistance to forcedopening as a result of a vehicle collision. A further object is toprovide an apparatus that assists the assembly of latches and likemechanisms to a vehicle door having an inner and outer door skin mountedon a strengthening structure. Another object of the invention is toprovide a method of fixing door latches to such doors.

[0007] According to one aspect the invention comprises a vehicle doorcomprising a strengthening structure, an inner door skin and a latchmechanism to be housed within the door, said mechanism having engagementmeans that co-operate with the strengthening structure to allow themechanism to be presented for rigid fixing within the door after theinner skin has been positioned relative to the strengthening structure;wherein at least one fixing means rigidly holds both the inner door skinand the latch mechanism to the strengthening structure.

[0008] According to another aspect the invention comprises a latchmechanism, adapted to be fixed to both a door strengthening structureand an inner door skin, having engagement means that co-operate with astrengthening structure to allow the mechanism to be presented for rigidfixing within a vehicle door after the inner skin has been positionedrelative to the strengthening structure; and wherein a single fixingmeans may rigidly hold both the latch mechanism and an inner door skinto a strengthening structure.

[0009] In a further aspect the invention comprises a method of fixing alatch mechanism to a vehicle door comprising the steps of:

[0010] a. non rigidly attaching a latch mechanism, so that it ispositioned for subsequent rigid fixing, to a strengthening structureusing engagement means fixed to the latch mechanism that co-operate withthe strengthening structure;

[0011] b. positioning an inner door skin relative to the strengtheningstructure; and

[0012] c. rigidly fixing both the inner door skin and the latchmechanism to the strengthening structure by at least one fixing means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] An embodiment of the invention will now be described by referenceto the following diagrammatic illustrations in which:

[0014]FIG. 1 shows a section of part of a vehicle door in plan view, and

[0015]FIG. 2 shows a perspective view of a strengthening structure and alatch mechanism according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016]FIG. 1 schematically shows in plan view that part of a vehicledoor 10 near to the door latch mechanism 22. The door comprises astrengthening structure 12 housed within an outer door skin 16 and aninner door skin 18. The strengthening structure 12 is generally elongateand tubular, of hollow cross section and has a plate 14 attached to orformed at one end. Plate 14 may be attached to the strengtheningstructure 12 by various means, such as by welding or by screws (notshown). Plate 14 has—a “V-shaped” notch 34, provided to allow passage ofa body mounted latch striker so that a latch mechanism 22 can functionand engage the striker. Plate 14 has three holes 26 to allow rigidattachment of the latch mechanism 22 to plate 14 of strengtheningstructure 12. Latch mechanism 22 may take many forms but will always behoused within the door between the door skins near the rim portion 20 ofinner door skin 18, in this case a rear edge of a side opening doorhinged at its front edge. The rim of door skin 20 also has three holes(not shown) configured to align with holes 26 in plate 14 when latchmechanism 22 is rigidly fixed to the door.

[0017] Latch mechanism 22 has an engagement means comprising aprotrusion 28 that cooperates with a hole 32 in strengthening structure12 to allow fixing of the latch (see below). In the present embodimentprotrusion 28 takes the form of a flexible spigot with deformable teeth30, made of plastics material and attached to the latch mechanism byconventional means: This is a preferable feature that allows sufficientflexibility or toleranced play in the fit between three fixing means 24and holes 26 etc., to insure that the fixing means 24 when fitted causethe latch to be positioned correctly relative to the strengtheningstructure 12, optionally in conjunction with other elements such as atongue and slot or hook (not shown). The fixing means of the presentembodiment are threaded fasteners in the form of screws.

[0018] Thus, during assembly of the door, the outer door skin 16 isattached to the strengthening structure 12, the latch mechanism 22 isnon-rigidly attached to the strengthening structure 12 by means ofengagement means 28 (spigot) and then the inner door skin 22 ispositioned against the inside of the strengthening structure 12 forfixing. The inner skin 18 is fixed in part to the strengtheningstructure 12 by three screws 24 that pass through the holes in the rim20 of the inner skin, through the holes 26 in plate 14 and thereby intothreaded bores in the latch mechanism (not shown). On tightening screws24 latch mechanism 22 is rigidly fixed to strengthening structure 12 inthe correct position relative to the rest of the door.

[0019] The door will also typically have a glass window 36 retractablymounted on guide channels 38 (only one shown). Guide channels 38 may beformed part of a frame strengthening structure, for example using aframe with a “U-shaped” cross section.

[0020] The strengthening structure may take a variety of forms, forexample it may comprise a frame located between the inner and outer doorskin near the edge of the door. It may comprise such a frame with one ormore side impact bars. The cross section of the frame members/bars canbe other than tubular, for example “L” or “U” shaped. In another aspect,plate 14 may be formed as an integral part of strengthening structure 12and/or strengthening structure 12 may itself be formed by joining morethan one elongated component.

[0021] The protrusion 28 may be formed or attached to either the latchmechanism or the strengthening structure. The protrusion may take theform of a tongue or a hook. The generally cylindrically shaped spigot 28is described above by way of example only. The spigot can have variouscross section shapes and may be tubular or non tubular in form. Thedeformable teeth 30 may be replaced by other fixing means such asdeformable prongs that engage the inside rim of fixing hole 32.

[0022] Alternatively, but less preferably, the latch mechanism may benon-rigidly held in place to the strengthening structure by a clippingarrangement between the latch mechanism and the strengthening structure,such an arrangement not requiring a slot, aperture or a recess thatcooperate with a protrusion.

[0023] The invention conveniently allows a latch mechanism to be looselyand temporarily held in position ready for rigid fixing at the time offixing the inner door skin. The door of the invention has enhancedresistance to forced opening of the lock during a collision as the lockmechanism is directly fixed to a strengthening structure designed toresist impact, especially side impact. It is important to prevent doorsopening during a collision as the structure is significantly more rigidif the door remains in place and is therefore able to stiffen the sidestructure of the vehicle.

[0024] The foregoing description is only exemplary of the principles ofthe invention. Many modifications and variations of the presentinvention are possible in light of the above teachings. The preferredembodiments of this invention have been disclosed, however, so that oneof ordinary skill in the art would recognize that certain modificationswould come within the scope of this invention. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described. For thatreason the following claims should be studied to determine the truescope and content of this invention.

What is claimed is:
 1. A vehicle door comprising: a strengtheningstructure; an inner door skin; a latch mechanism housed within thevehicle door; an engagement member to rigidly fix the latch mechanismwithin the vehicle door after the inner door skin has been positionedrelative to the strengthening structure; and at least one fixing memberto rigidly hold the inner door skin and the latch mechanism to thestrengthening structure.
 2. The vehicle door according to claim 1wherein the strengthening structure is rigidly held between the latchmechanism and the inner door skin.
 3. The vehicle door according toclaim 2 wherein the strengthening structure includes an elongatedsection and a plate section formed in a plane generally orthogonal to alongitudinal axis of the elongated section.
 4. The vehicle dooraccording to claim 3 wherein the plate section is attached to thestrengthening structure.
 5. The vehicle door according to claim 1wherein the at least one fixing member engages a rim portion of theinner door skin.
 6. The vehicle door according to claim 1 wherein theengagement member is a protrusion on the latch mechanism which engagesone of a corresponding slot, an aperture and a recess in thestrengthening structure.
 7. The vehicle door according to claim 1wherein the engagement member is a protrusion on the strengtheningstructure which engages one of a corresponding slot, an aperture and arecess in the latch mechanism.
 8. The vehicle door according to claim 6wherein the protrusion is one of a tongue, a hook, a screw, and aspigot.
 9. The vehicle door according to claim 8 wherein the protrusionis flexible to assist with engagement in one of the slot, the aperture,and the recess.
 10. The vehicle door according to claim 6 wherein theprotrusion is one of a flexible screw and a spigot with ratchet teeth.11. The vehicle door according to claim 1 further including an outerskin adjacent to the strengthening structure.
 12. The vehicle dooraccording to claim 7 wherein the protrusion is one of a tongue, a hook,a screw, and a spigot.
 13. The vehicle door according to claim 12wherein the protrusion is flexible to assist with engagement in one ofthe slot, the aperture, and the recess.
 14. The vehicle door accordingto claim 7 wherein the protrusion is one of a flexible screw and aspigot with ratchet teeth.
 15. A latch mechanism, adapted to be fixed toboth a door strengthening structure and an inner door skin, comprising:an engagement member that cooperates with the door strengtheningstructure to rigidly fix the latch mechanism within a vehicle door afterthe inner door skin has been positioned relative to the strengtheningstructure; and a fixing member that rigidly holds both the latchmechanism and the inner door skin to the strengthening structure.
 16. Amethod of fixing a latch mechanism to a vehicle door comprising thesteps of: (a) flexibly attaching the latch mechanism to a strengtheningstructure by an engagement member fixed to the latch mechanism, and thelatch mechanism cooperates with the strengthening structure; (b)positioning an inner door skin relative to the strengthening structure;and (c) rigidly fixing both the inner door skin and the latch mechanismto the strengthening stricture by at least one fixing member.